Load early warning device of photovoltaic power station

Abstract

The utility model discloses a load early warning device of a photovoltaic power station, and relates to the technical field of power stations, the load early warning device comprises an inverter, the input end of the inverter receives the output of the photovoltaic power station; a primary coil of the transformer is connected with the output end of the inverter; the input end of the rectification filter circuit is connected with the secondary coil of the transformer; the first input end of the comparison circuit is connected with the output end of the rectification filter circuit, and the second input end of the comparison circuit is connected with a reference source circuit; the control module is respectively connected with the comparison circuit and the prompt module, and when the voltage of the photovoltaic power station is lower than a preset threshold value, the control module controls the prompt module to give out a load early warning prompt so as to prepare countermeasures in advance for possible power grid fluctuation.

Description

Technical Field

[0001] The utility model relates to the technical field of power stations, in particular to a load early warning device for a photovoltaic power station. Background Art

[0002] A photovoltaic power station refers to a power generation system that uses solar energy and adopts special materials such as crystalline silicon panels, inverters and other electronic components. It is a photovoltaic power generation system that is connected to the power grid and transmits electricity to the power grid. A photovoltaic power station with a complete set of functions usually has one or more photovoltaic arrays for receiving solar energy, a transformer for converting the electricity generated by the photovoltaic array, and an energy storage device electrically connected to the transformer. The energy storage device is used to store electricity and transmit it to external power-consuming equipment through the power grid.

[0003] Due to the randomness of photovoltaic light, it is easy to cause fluctuations in the power grid of the power station, which has a certain impact on the generation, collection and transmission of electricity. Therefore, it is necessary to predict the load of the photovoltaic power station in order to prepare countermeasures in advance for possible fluctuations in the future. Utility Model Content

[0004] The purpose of the utility model is to provide a load warning device for a photovoltaic power station. When the voltage of the photovoltaic power station is lower than a preset threshold, the control module controls the prompt module to issue a load warning prompt so as to prepare countermeasures in advance for possible fluctuations.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] One aspect of an embodiment of the present utility model provides a load warning device for a photovoltaic power station, the load warning device comprising: an inverter, the input end of the inverter receiving the output of the photovoltaic power station; a transformer, the primary coil of the transformer connected to the output end of the inverter; a rectifier filter circuit, the input end of the rectifier filter circuit connected to the secondary coil of the transformer; a comparison circuit, the first input end of the comparison circuit connected to the output end of the rectifier filter circuit, and the second input end of the comparison circuit connected to the reference source circuit; a control module and a prompt module, the control module being connected to the comparison circuit and the prompt module respectively, and when the voltage of the photovoltaic power station is lower than a preset threshold, the control module controls the prompt module to issue a load warning prompt.

[0007] In some embodiments, the load warning device also includes a voltage divider circuit, which includes a first resistor and a second resistor, one end of the first resistor is connected to the output end of the rectifier and filter circuit, the other end of the first resistor is connected to one end of the second resistor and the first input end of the comparison circuit, and the other end of the second resistor is grounded.

[0008] In some embodiments, the comparison circuit includes a comparator, a third resistor, a fourth resistor and a fifth resistor, the non-inverting input of the comparator is connected to the other end of the first resistor and one end of the second resistor through the third resistor, the inverting input of the comparator is connected to one end of the fourth resistor, the other end of the fourth resistor is connected to the reference source circuit, the output of the comparator is connected to one end of the fifth resistor, and the other end of the fifth resistor is connected to the control module.

[0009] In some embodiments, the load warning device also includes a delay circuit, which is arranged between the comparison circuit and the control module. The delay circuit includes a PNP transistor, a sixth resistor, a seventh resistor, an eighth resistor, a first capacitor and a second capacitor. The base of the PNP transistor is connected to the positive electrode of the first capacitor and the other end of the fifth resistor through the sixth resistor, the emitter of the PNP transistor is connected to one end of the seventh resistor, one end of the second capacitor and the control module, the other end of the seventh resistor is connected to a second power supply, the collector of the PNP transistor is connected to one end of the eighth resistor, the negative electrode of the first capacitor, the other end of the second capacitor and the other end of the eighth resistor are grounded; when the voltage of the photovoltaic power station is lower than a preset threshold and lasts for a set period of time, the control module controls the prompt module to issue a load warning prompt.

[0010] In some embodiments, the reference source circuit includes a first NPN transistor, a voltage-stabilizing diode, a ninth resistor and a third capacitor, the collector of the first NPN transistor is connected to one end of the ninth resistor, one end of the third capacitor and a third power supply, the base of the first NPN transistor is connected to the other end of the ninth resistor and the negative electrode of the voltage-stabilizing diode, the positive electrode of the voltage-stabilizing diode and the other end of the third capacitor are grounded, and the emitter of the first NPN transistor is connected to the other end of the fourth resistor.

[0011] In some embodiments, the load warning device also includes a prompt module, which includes a second NPN transistor, a tenth resistor, an eleventh resistor and a prompt light, the collector of the second NPN transistor is connected to the third power supply through the tenth resistor, the base of the second NPN transistor is connected to the control module, the emitter of the second NPN transistor is connected to the positive pole of the prompt light through the eleventh resistor, and the negative pole of the prompt light is grounded.

[0012] In some embodiments, the prompt module further includes a twelfth resistor and a speaker, the emitter of the second NPN transistor is connected to the positive electrode of the speaker through the twelfth resistor, and the negative electrode of the speaker is grounded.

[0013] In some embodiments, the prompt module further includes a diode, the cathode of the diode is connected to the anode of the speaker, and the anode of the diode is connected to the cathode of the speaker.

[0014] In some embodiments, the rectifier and filter circuit includes a rectifier bridge, a fourth capacitor and a fifth capacitor. The input end of the rectifier bridge is connected to the secondary coil of the transformer, the positive output end of the rectifier bridge is connected to the positive electrode of the fourth capacitor, one end of the fifth capacitor and one end of the first resistor, the negative output end of the rectifier bridge is used as a ground point, and the negative electrode of the fourth capacitor and the other end of the fifth capacitor are grounded.

[0015] A load warning device for a photovoltaic power station according to an embodiment of the present invention has at least the following beneficial effects: In some embodiments, when the voltage of the photovoltaic power station falls below a preset threshold, the control module controls the prompt module to issue a load warning, thereby preparing for possible fluctuations in the power station's electrical grid. In other embodiments, a delay circuit is added. When the voltage of the photovoltaic power station falls below a preset threshold for a set period of time, the control module controls the prompt module to issue a load warning. The addition of a delay circuit in this application can prevent misjudgments or short-term voltage fluctuations, thereby improving the accuracy of the warning.

[0016] It should be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0018] Figure 1 is a principle block diagram of a load warning device according to an embodiment;

[0019] Figure 2 1 is a schematic diagram of a rectifier and filter circuit and a schematic diagram of a comparison circuit according to an embodiment;

[0020] Figure 3 is a schematic diagram of a delay circuit according to an embodiment;

[0021] Figure 4 is a schematic diagram of a reference source circuit according to an embodiment;

[0022] Figure 5 4 is a circuit diagram of a prompt module according to an embodiment. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the technical features being referred to. Therefore, a feature specified as "first," "second," or "third" may explicitly or implicitly include one or more of such features. In the description of this utility model, unless otherwise specified, "plurality" means two or more.

[0025] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "connected," "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0026] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these example embodiments are provided so that the description of this disclosure will be more comprehensive and complete, and will fully convey the concepts of the example embodiments to those skilled in the art. The accompanying drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale. Identical reference numerals in the figures indicate identical or similar parts, and thus repeated descriptions thereof will be omitted.

[0027] The technical solutions of the embodiments of the present application are briefly described below:

[0028] According to some embodiments, Figure 1 As shown, the present application provides a load warning device for a photovoltaic power station, the load warning device comprising:

[0029] Inverter, the input end of the inverter receives the output of the photovoltaic power station;

[0030] A transformer, wherein the primary coil of the transformer is connected to the output terminal of the inverter;

[0031] A rectifier and filter circuit, wherein the input end of the rectifier and filter circuit is connected to the secondary coil of the transformer;

[0032] A comparison circuit, wherein a first input terminal of the comparison circuit is connected to the output terminal of the rectifier and filter circuit, and a second input terminal of the comparison circuit is connected to the reference source circuit;

[0033] The control module and the prompt module are connected to the comparison circuit and the prompt module respectively. When the voltage of the photovoltaic power station is lower than the preset threshold, the control module controls the prompt module to issue a load warning prompt.

[0034] The general operating principle of the above embodiment is as follows: after receiving the output of the photovoltaic power station, the inverter converts the direct current (DC) power from the photovoltaic power station into alternating current (AC). The transformer steps down the inverted AC power to a voltage suitable for measurement. The rectifier and filter circuit then rectifies and filters the stepped-down AC power into a stable DC power supply V1. A comparator circuit then compares the DC power supply V1 with a reference source stabilized by a reference source circuit. When the output voltage of the photovoltaic power station is stable, the voltage of the DC power supply V1 is higher than the voltage of the reference source. The comparator circuit outputs a first signal to the control module, which determines that the voltage of the photovoltaic power station is stable and disables the prompt module. When the output voltage of the photovoltaic power station decreases and falls below a preset threshold, the voltage of the DC power supply V1 is lower than the voltage of the reference source. The comparator circuit outputs a second signal to the control module, which determines that the voltage of the photovoltaic power station is unstable and activates the prompt module to issue a load warning, prompting personnel to prepare for potential grid fluctuations.

[0035] The following is in conjunction with the appendix of this manual Figures 1 to 5 , the preferred embodiments of the present disclosure are further elaborated in detail.

[0036] According to some embodiments, Figure 2 As shown, the load warning device also includes a voltage divider circuit, which includes a first resistor R1 and a second resistor R2. One end of the first resistor R1 is connected to the output end of the rectifier and filter circuit, the other end of the first resistor R1 is connected to one end of the second resistor R2 and the first input end of the comparison circuit, and the other end of the second resistor R2 is grounded.

[0037] According to some embodiments, Figure 2 As shown, the comparison circuit includes a comparator U, a third resistor R3, a fourth resistor R4 and a fifth resistor R5. The non-inverting input terminal of the comparator U is connected to the other end of the first resistor R1 and one end of the second resistor R2 through the third resistor R3. The inverting input terminal of the comparator U is connected to one end of the fourth resistor R4. The other end of the fourth resistor R4 is connected to the reference source circuit. The output terminal of the comparator U is connected to one end of the fifth resistor R5. The other end of the fifth resistor R5 is connected to the control module.

[0038] Further, such as Figure 3As shown, the load warning device also includes a delay circuit, which is arranged between the comparison circuit and the control module. The delay circuit includes a PNP transistor QP, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first capacitor C1 and a second capacitor C2. The base of the PNP transistor QP is connected to the positive electrode of the first capacitor C1 and the other end of the fifth resistor R5 through the sixth resistor R6, the emitter of the PNP transistor QP is connected to one end of the seventh resistor R7, one end of the second capacitor C2 and the control module, the other end of the seventh resistor R7 is connected to the second power supply V2, the collector of the PNP transistor QP is connected to one end of the eighth resistor R8, and the negative electrode of the first capacitor C1, the other end of the second capacitor C2 and the other end of the eighth resistor R8 are grounded;

[0039] When the voltage of the photovoltaic power station is lower than the preset threshold and continues for a set period of time, the control module controls the prompt module to issue a load warning prompt.

[0040] Based on the operating principle of the above embodiment, comparator U compares DC power supply V1 with a reference source stabilized by a reference source circuit. When the output voltage of the photovoltaic power station is stable, the voltage of DC power supply V1 is higher than the voltage of the reference source. Comparator U outputs a high-level signal to the base of PNP transistor QP, turning off the PNP transistor QP. The control module receives the high-level signal and determines that the voltage of the photovoltaic power station is stable, deactivating the prompt module. When the output voltage of the photovoltaic power station falls below a preset threshold for a set period of time, the voltage of DC power supply V1 falls below the voltage of the reference source. Comparator U outputs a low-level signal to the base of PNP transistor QP, turning on the PNP transistor QP. The control module receives the low-level signal and determines that the voltage of the photovoltaic power station is unstable. The prompt module activates the load warning prompt, prompting personnel to prepare for possible power grid fluctuations.

[0041] The preset threshold is determined by the voltage of the reference source, which can be set according to actual needs. The set duration is determined by the charging time of the first capacitor C1, which is determined by the capacitance of the first capacitor C1, which can be set according to actual needs.

[0042] According to some embodiments, Figure 4 As shown, the reference source circuit includes a first NPN transistor QN1, a Zener diode DZ, a ninth resistor R9 and a third capacitor C3. The collector of the first NPN transistor QN1 is connected to one end of the ninth resistor R9, one end of the third capacitor C3 and the third power supply V3. The base of the first NPN transistor QN1 is connected to the other end of the ninth resistor R9 and the cathode of the Zener diode DZ. The anode of the Zener diode DZ and the other end of the third capacitor C3 are grounded. The emitter of the first NPN transistor QN1 is connected to the other end of the fourth resistor R4.

[0043] The reference source circuit is used to stabilize the voltage. When the output voltage of the photovoltaic power station decreases, the reference source circuit can still be stabilized at an interval value, so that the comparator U can compare the output voltage of the photovoltaic power station to see if it has decreased.

[0044] According to some embodiments, Figure 5 As shown, the load warning device also includes a prompt module, which includes a second NPN transistor QN2, a tenth resistor R10, an eleventh resistor R11 and a prompt light LED. The collector of the second NPN transistor QN2 is connected to the third power supply V3 through the tenth resistor R10, the base of the second NPN transistor QN2 is connected to the control module, the emitter of the second NPN transistor QN2 is connected to the positive electrode of the prompt light LED through the eleventh resistor R11, and the negative electrode of the prompt light LED is grounded.

[0045] Further, such as Figure 5 As shown, the prompt module further includes a twelfth resistor R12 and a speaker LS. The emitter of the second NPN transistor QN2 is connected to the positive electrode of the speaker LS through the twelfth resistor R12, and the negative electrode of the speaker LS is grounded.

[0046] Further, such as Figure 5 As shown, the prompt module further includes a diode D, the cathode of the diode D is connected to the anode of the speaker LS, and the anode of the diode D is connected to the cathode of the speaker LS.

[0047] The speaker LS is provided with an inductive element, and the diode D is used to allow the inductive element inside the speaker LS to continue to flow through the diode D when the speaker LS is powered off.

[0048] According to some embodiments, the rectifier and filter circuit includes a rectifier bridge, a fourth capacitor C4, and a fifth capacitor C5. The input end of the rectifier bridge is connected to the secondary coil of the transformer. The positive output end of the rectifier bridge is connected to the positive electrode of the fourth capacitor C4, one end of the fifth capacitor C5, and one end of the first resistor R1. The negative output end of the rectifier bridge serves as a ground, and the negative electrode of the fourth capacitor C4 and the other end of the fifth capacitor C5 are grounded. The rectifier bridge is used to rectify alternating current (AC) to direct current (DC). The fourth capacitor C4 is a large capacitor used to filter low frequencies. The fifth capacitor C5 is a small capacitor used to filter high frequencies.

[0049] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0050] While the present disclosure has been described with reference to several exemplary embodiments, it should be understood that the terms used are illustrative and exemplary rather than restrictive. Since the present disclosure can be embodied in various forms without departing from the spirit or substance of the application, it should be understood that the above-described embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope of the appended claims. Therefore, all changes and modifications that fall within the scope of the claims or their equivalents are intended to be covered by the appended claims.

Claims

1. A load warning device for a photovoltaic power station, characterized in that: The load warning device includes: an inverter, wherein an input end of the inverter receives an output of the photovoltaic power station; a transformer, wherein the primary coil of the transformer is connected to the output end of the inverter; A rectifier and filter circuit, wherein an input end of the rectifier and filter circuit is connected to the secondary coil of the transformer; a comparison circuit, wherein a first input terminal of the comparison circuit is connected to the output terminal of the rectification and filtering circuit, and a second input terminal of the comparison circuit is connected to a reference source circuit; A control module and a prompt module, wherein the control module is connected to the comparison circuit and the prompt module respectively, and when the voltage of the photovoltaic power station is lower than a preset threshold, the control module controls the prompt module to issue a load warning prompt.

2. The load warning device according to claim 1, characterized in that: The load warning device also includes a voltage divider circuit, which includes a first resistor and a second resistor. One end of the first resistor is connected to the output end of the rectifier and filter circuit, the other end of the first resistor is connected to one end of the second resistor and the first input end of the comparison circuit, and the other end of the second resistor is grounded.

3. The load warning device according to claim 2, characterized in that: The comparison circuit includes a comparator, a third resistor, a fourth resistor and a fifth resistor. The non-inverting input of the comparator is connected to the other end of the first resistor and one end of the second resistor through the third resistor. The inverting input of the comparator is connected to one end of the fourth resistor, and the other end of the fourth resistor is connected to the reference source circuit. The output of the comparator is connected to one end of the fifth resistor, and the other end of the fifth resistor is connected to the control module.

4. The load warning device according to claim 3, characterized in that: The load warning device also includes a delay circuit, which is arranged between the comparison circuit and the control module. The delay circuit includes a PNP transistor, a sixth resistor, a seventh resistor, an eighth resistor, a first capacitor, and a second capacitor. The base of the PNP transistor is connected to the positive electrode of the first capacitor and the other end of the fifth resistor through the sixth resistor, the emitter of the PNP transistor is connected to one end of the seventh resistor, one end of the second capacitor, and the control module, the other end of the seventh resistor is connected to a second power supply, the collector of the PNP transistor is connected to one end of the eighth resistor, and the negative electrode of the first capacitor, the other end of the second capacitor, and the other end of the eighth resistor are grounded; When the voltage of the photovoltaic power station is lower than a preset threshold and lasts for a set period of time, the control module controls the prompt module to issue a load warning prompt.

5. The load warning device according to claim 3, characterized in that: The reference source circuit includes a first NPN transistor, a voltage-stabilizing diode, a ninth resistor and a third capacitor, the collector of the first NPN transistor is connected to one end of the ninth resistor, one end of the third capacitor and a third power supply, the base of the first NPN transistor is connected to the other end of the ninth resistor and the negative electrode of the voltage-stabilizing diode, the positive electrode of the voltage-stabilizing diode and the other end of the third capacitor are grounded, and the emitter of the first NPN transistor is connected to the other end of the fourth resistor.

6. The load warning device according to claim 1, characterized in that: The load warning device also includes a prompt module, which includes a second NPN transistor, a tenth resistor, an eleventh resistor and a prompt light. The collector of the second NPN transistor is connected to the third power supply through the tenth resistor, the base of the second NPN transistor is connected to the control module, the emitter of the second NPN transistor is connected to the positive electrode of the prompt light through the eleventh resistor, and the negative electrode of the prompt light is grounded.

7. The load warning device according to claim 6, characterized in that: The prompt module further includes a twelfth resistor and a speaker. The emitter of the second NPN transistor is connected to the positive electrode of the speaker through the twelfth resistor, and the negative electrode of the speaker is grounded.

8. The load warning device according to claim 7, characterized in that: The prompt module further includes a diode, the cathode of the diode is connected to the anode of the speaker, and the anode of the diode is connected to the cathode of the speaker.

9. The load warning device according to claim 2, characterized in that: The rectifier and filter circuit includes a rectifier bridge, a fourth capacitor and a fifth capacitor. The input end of the rectifier bridge is connected to the secondary coil of the transformer, the positive output end of the rectifier bridge is connected to the positive electrode of the fourth capacitor, one end of the fifth capacitor and one end of the first resistor, the negative output end of the rectifier bridge is used as a ground point, and the negative electrode of the fourth capacitor and the other end of the fifth capacitor are grounded.

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